<template>
  <div class="xtx-infinate-loading" ref="target">
    <div class="loading" v-if="loading">
      <span class="img"></span>
      <span class="text">正在加载...</span>
    </div>
    <div class="none" v-if="finished">
      <span class="img"></span>
      <span class="text">亲，没有更多了</span>
    </div>
  </div>
</template>

<script>
import { ref } from '@vue/reactivity'
import { useIntersectionObserver } from '@vueuse/core'
export default {
  name: 'XtxInfiniteLoading',
  props: {
    loading: {
      type: Boolean,
      default: false
    },
    finished: {
      type: Boolean,
      default: false
    }
  },
  setup (props, { emit }) {
    const target = ref(null)
    // 监听target是否进入可视区
    useIntersectionObserver(target, ([isIntersecting]) => {
      if (isIntersecting) {
        console.log('进入')
        // 触发加载事件的条件：
        // 1.必须请求完成
        // 2.数据还没全部加载完
        if (!props.loading && !props.finished) {
          emit('infinite')
        }
      }
    }, { threshold: 0 })
    return { target }
  }
}
</script>

<style lang="less" scoped>
.xtx-infinate-loading{
  .loading{
    display: flex;
    align-items: center;
    justify-content: center;
    height: 200px;
    .img{
      width: 50px;
      height: 50px;
      background: url(../../assets/images/load.gif) no-repeat center / contain;
    }
    .text{
      color:#999;
      font-size: 16px;
    }
  }
  .none{
    display: flex;
    align-items: center;
    justify-content: center;
    height: 200px;
    .img{
      width: 200px;
      height: 134px;
      background: url(../../assets/images/none.png) no-repeat center / contain;
    }
    .text{
      color:#999;
      font-size: 16px;
    }
  }
}
</style>
